Department of Engineering Sciences, Pakistan Navy Engineering College (PNEC), National University of Sciences and Technology (NUST), Karachi, Pakistan.
Department of Materials Engineering, NED University of Engineering and Technology, Karachi, Pakistan.
PLoS One. 2024 Jan 16;19(1):e0296793. doi: 10.1371/journal.pone.0296793. eCollection 2024.
Ceramics are the oxides of metals and nonmetals with excellent compressive strength. Ceramics usually exhibit inert behavior at high temperatures. Magnesium aluminate (MgAl2O4), a member of the ceramic family, possesses a high working temperature up to 2000°C, low thermal conductivity, high strength even at elevated temperatures, and good corrosion resistance. Moreover, Magnesium Aluminate Nanoparticles (MANPs) can be used in the making of refractory crucible applications. This study focuses on the thermal behavior of Magnesium Aluminate Nanoparticles (MANPs) and their application in the making of refractory crucibles. The molten salt method is used to obtain MANPs. The presence of MANPs is seen by XRD peaks ranging from 66° to 67°. The determination of the smallest crystallite size of the sample is achieved by utilizing the Scherrer formula and is found to be 15.3 nm. The SEM micrographs provided further information, indicating an average particle size of 91.2 nm. At 600°C, DSC curves show that only 0.05 W/g heat flows into the material, and the TGA curve shows only 3% weight loss, which is prominent for thermal insulation applications. To investigate the thermal properties, crucibles of pure MANPs and the different compositions of MANPs and pure alumina are prepared. During the sintering, cracks appear on the crucible of pure magnesium aluminate. To explore the reason for crack development, tablets of MgAl2O4 are made and sintered at 1150°C. Ceramography shows the crack-free surfaces of all the tablets. Results confirm the thermal stability of MANPs at high temperatures and their suitability for melting crucible applications.
陶瓷是金属和非金属的氧化物，具有优异的抗压强度。陶瓷通常在高温下表现出惰性行为。镁铝尖晶石（MgAl2O4）是陶瓷家族的一员，具有高达 2000°C 的工作温度、低导热性、即使在高温下也具有高强度和良好的耐腐蚀性。此外，镁铝尖晶石纳米颗粒（MANPs）可用于制造耐火坩埚应用。本研究重点研究了镁铝尖晶石纳米颗粒（MANPs）的热行为及其在制造耐火坩埚中的应用。采用熔融盐法获得 MANPs。通过 XRD 峰（范围从 66°到 67°）可以看出 MANPs 的存在。通过利用谢勒公式确定样品的最小晶粒尺寸，发现其为 15.3nm。SEM 显微照片提供了进一步的信息，表明平均粒径为 91.2nm。在 600°C 时，DSC 曲线显示只有 0.05W/g 的热量流入材料，TGA 曲线显示只有 3%的重量损失，这对于隔热应用非常显著。为了研究热性能，制备了纯 MANPs 和不同组成的 MANPs 和纯氧化铝的坩埚。在烧结过程中，纯镁铝酸盐坩埚上出现了裂纹。为了探究裂纹发展的原因，制备了 MgAl2O4 片并在 1150°C 下烧结。陶瓷学显示所有片剂的表面均无裂纹。结果证实了 MANPs 在高温下的热稳定性及其在熔融坩埚应用中的适用性。
